This invention relates to improved orally utilizable compositions having a flavor with good initial strength and which flavor is controllably released (under the hydrolytic conditions of the human mouth cavity) at a consistently high level over an extended period of time; to processes for preparing such orally utilizable compositions; to flavor compositions useful in preparing same and to processes for preparing such specially useful flavoring compositions.
The term "orally utilizable compositions" includes such materials as chewing gum, chewable medicinal tablets such as chewable vitamin tablets, chewing tobacco and toothpaste.
There has been considerable work performed relating to orally utilizable substances such as chewing gum, chewable medicinal tablets, chewing tobacco and toothpaste whereby such orally utilizable substances have a flavor impact both initially and over an extended period of time. Problems have arisen in attempting to create such orally utilizable compositions wherein part of the flavor is available for immediate results whereas another part provides the effect of such flavor gradually over extended periods of time. Such problems include the continuous distribution of "initial impact" and "extended release" flavor over the entire mass of the orally utilizable composition as well as commercial manufacture of same.
U.S. Pat. No. 1,526,039, for example, teaches that if an essential oil or flavoring is combined with chewing gum base in a finely divided condition, and the particles of the flavoring or oil are encased in a suitable covering so as not to contact directly the gum during manufacture, the deleterious effect of the flavoring on the gum is prevented or largely reduced. It is further stated therein that:
"When the emulsion is added to the gum base, it is thoroughly mixed therewith by the usual means employed for mixing the flavoring material with such base.
The production of the emulsion serves to break up the essential oil into fine particles and to encase these particles in the emulsifying material, so that when the emulsion is added to the gum mass, the essential oil to a large degree is prevented from coming into direct contact with the base, and from having deleterious action thereon."
U.S. Pat. No. 2,886,440 teaches a method of preparing a chewing gum characterized by "extended flavor perception time, true flavor character, and high degree of flavor release comprising the steps of forming a spray-dried emulsion of a volatile, water-immiscible flavoring agent encapsulated within finely divided particles of gelatin, and substantially uniformly distributing said gelatin encapsulated flavoring agent within an all-enveloping mass of a chewable gum base." The use of separate "fixed" and "unfixed" flavor portions is also taught but there is no disclosure therein of the principal of this invention, to wit: mixing the fixed and unfixed flavor portions with a suspension agent prior to adding to the chewing gum base.
U.S. Pat. No. 2,886,446 teaches a chewing gum comprising (i) smaller particles of gelatin characterized by faster liberation of flavor and (ii) larger particles of gelatin characterized by slower liberation of flavor, each of the gelatin particles containing dispersed therewithin, in dried emulsion form, discrete micro-droplets of a volatile water-immiscible flavoring agent, and an all-enveloping mass of a chewable gum base within which the particles are substantially uniformly distributed whereby the flavor is released substantially evenly and uniformly over the extended chewing time.
U.S. Pat. No. 2,886,445 teaches that:
"It is possible to obtain a flavoring composition, particularly adapted for use in chewing gum which permits attainment of a product characterized by extended flavor preception time, true flavor character, and release of a large proportion of flavoring agent. This flavoring composition comprises finely divided particles of a dried hardened gelatin emulsion containing discrete micro-droplets of a volatile, water-immiscible flavoring agent. Preparation of the flavoring composition of this invention may be effected by encapsulating discrete micro-droplets of volatile, water-immiscible flavoring agent within finely divided particles of a dried emulsion of hardened gelatin."
U.S. Pat. No. 2,886,449 teaches:
"A chewing gum containing a flavoring composition characterized by an extended flavor perception time, true flavor character, controlled release of a large portion of flavoring agent, and reduction in amount of flavor oil required (which) may be prepared by the process comprising forming a gelatin-coacervated flavor, and substantially uniformly distributing said gelatin-coacervated flavor within an all-enveloping mass of a chewable gum base. The product chewing gum . . . comprises . . . finely divided particles of coacervated gelatin containing a water-immiscible flavoring agent therewithin and an all-enveloping mass of a chewing gum base within which the particles are substantially distributed."
The utilization of sustained released flavor containing capsules in such materials as chewing gum and mecidinal tablets is also taught in British Pat. No. 1,205,764.
The use of sustained release flavor capsules in conjunction with polyethylene glycols (which are taught to be employed to disolventize the capsules) is set forth in British Pat. No. 1,318,799.
Furthermore, described in U.S. Pat. No. 3,920,849 may be either chewing gum compositions, chewable medicinal tablets, chewing tobacco or toothpaste having an oral intake, a high flavor intensity release substantially evenly and uniformly, over an extended oral utilization time in the mouth cavity; the orally utilizable compositions containing a non-confined flavor oil, a flavor oil which is physically entrapped in solid particles and a suspending agent such as silica, xanthan gum and ethyl cellulose; the non-confined flavor oil, the entrapped oil and the suspension agent being premixed prior to addition to either of the chewing gum base, the chewing tobacco or the chewable medicinal tablet base or the toothpaste base.
Nothing in the prior art, however, indicates the use of hydroxypropyl cellulose as defined in U.S. Pat. No. 3,278,521 issued on Oct. 11, 1966 for taking the place of the suspension agents of U.S. Pat. No. 3,920,849.
Furthermore, German Offenlengungsschrift No. 2,826,042 published on Jan. 4, 1979 relying on Austrian priority document A4305-77 of June 17, 1977 discloses a condiment consisting of a salt admixed with (a) from 0.1 up to 0.5 weight percent of a terpene-free lemon oil bonded to a powdery character and (b) a terpene-free liquid lemon oil. In German Offenlengungsschrift No. 2,826,042 the condiment is prepared by mixing the dry salts with component (a), spraying the mixture with (b) and mixing through a mixer such as a mixing screw. Nothing in Offenlengungsschrift No. 2,826,042 implies that a hydroxypropyl cellulose material can be used as a suspending agent for the terpene-free liquid lemon oil.
The hydroxypropyl cellulose derivatives useful in the practice of our invention are particularly described in a paper entitled "Functional Helpmate To Development . . . Hydroxypropyl Cellulose/A New Water Soluble Cellulose Polymer", Klug, Vol. 24, 51, Food Technology, January, 1970 and a pamphlet entitled "Klucel.RTM./Hydroxypropyl Cellulose/Chemical and Physical Properties Published by Hercules Incorporated, 1976".